Rail Brake with Guide Wheels

ABSTRACT

A braking system is provided for rail equipment supported for rolling movement on the rails of a railway. The braking system includes a pair of braking elements arranged to be supported laterally spaced apart on the rail equipment for engaging the respective rails of the railway. Each braking element includes an upper brake block for selectively engaging a top side and a side brake block for selectively engaging an inner side of the corresponding rail. Actuators are provided for urging the braking elements downward and outward in relation to the rail equipment. The actuators engage the braking elements with the respective rails to provide a wedging action between respective inner sides of the rails. This arrangement provides considerable braking force using a relatively simple construction.

This application claims foreign priority benefits from Canadian Patent Application 2,858,412, filed Aug. 5, 2014.

FIELD OF THE INVENTION

The present invention relates to a braking system for rail equipment of the type which is supported for rolling movement on the rails of a railway, and more particularly, the present invention relates to a braking system which is movable between roadway and railway modes, and which is further operable between engaged and disengaged positions in the railway mode.

BACKGROUND

Vehicles such as maintenance trucks and construction equipment are known to be adapted for use on a railway by mounting high rail equipment on the vehicle in the form of additional wheels which are arranged to be supported on the rails. When braking however, known vehicles of this type generally rely on their conventional brakes normally used on roadways, which are not always sufficient when the vehicle is supported on the rails.

Other vehicles which are intended for use on railways such as trains have braking systems which are designed to directly engage the rails of the railway. These braking systems however are generally elaborate and complex arrangements which are intended to clamp the rails individually with considerable force. These systems can thus be costly to manufacture as well as costly to maintain for use with high rail equipment.

Canadian Patent No. 2,313,342 and U.S. Pat. No. 6,595,333 by Hamer et al disclose a braking system for rail equipment includes a pair of braking elements arranged to be supported laterally spaced apart on the rail equipment for engaging the respective rails of the railway. Each braking element includes an upper brake block for selectively engaging a top side and a side brake block for selectively engaging an inner side of the corresponding rail. Actuators are provided for urging the braking elements downward and outward in relation to the rail equipment. The actuators engage the braking elements with the respective rails to provide a wedging action between respective inner sides of the rails. In the railway mode, the braking elements must be supported in close engagement to the rails for ready actuation of the braking elements, but the positioning of the braking elements requires careful calibration of the support mechanism to ensure proper placement of the braking elements in the railway mode.

SUMMARY

According to one aspect of the present invention there is provided a braking system for rail equipment which is arranged to be supported on a pair of rails for movement in a longitudinal direction along the rails, the braking system comprising:

a pair of carriage assemblies, each carriage assembly comprising a frame member and a pair of guide wheels rotatably mounted on the frame member at longitudinally spaced positions;

rail equipment mounting means arranged to support the carriage assemblies on the rail equipment such that the carriage assemblies are movable between a railway position in which the guide wheels of the pair of carriage assemblies are arranged for rolling engagement along respective ones of the rails and a roadway position in which the carriage assemblies are spaced upwardly from the railway position;

a braking component comprising at least one brake block supported on each carriage assembly such that said at least one brake block is movable relative to the respective carriage assembly between an engaged position in which said at least one brake block engages the respective rail in a braking action and a disengaged position in which said at least one brake block is disengaged from the respective rail while the carriage assembly remains in the railway position; and

an actuator arranged to selectively urge the brake blocks of the carriage assemblies towards the engaged position.

The braking system of the present invention provides a simple structure which can be easily adapted to various vehicles. By providing guide wheels which engage the rails even when the braking elements are disengaged, the braking element can be accurately positioned for ready use in the railway mode as compared to previous arrangements. The guide wheels further permit the use of an active hydraulic pressure to maintain positive engagement and alignment with the rails.

When the rail equipment mounting means comprises hydraulic actuators for urging the carriage assemblies from the roadway position to the railway position, preferably the braking system further comprises a hydraulic supply in connection with the hydraulic actuators of the rail equipment mounting means which is arranged to supply an active hydraulic pressure at a prescribed pressure level to the hydraulic actuators of the rail equipment mounting means. Preferably the prescribed pressure level comprises a set-point pressure which can be controllably adjusted through a range of selectable pressures.

Each guide wheel may include a generally cylindrical portion arranged for rolling engagement along a top side of a head of the respective rail and an inner flange portion which protrudes radially outwardly from the generally cylindrical portion at an inner end thereof in proximity to an inner side of the head of the respective rail.

The rail equipment mounting means preferably arranged to support the carriage assemblies on the rail equipment such that the carriage assemblies are movable downwardly and laterally outwardly from the roadway position to the railway position.

The brake block of each carriage assembly preferably comprises an upper brake block arranged to engage a top side of a head of the respective rail and a side brake block arranged to engage an inner side of the head of the respective rail.

Preferably the brake blocks are slidably mounted on the respective carriage assemblies for sliding movement along respective axes extending downward and laterally outward from the disengaged position towards the engaged position.

Preferably each side brake block is fixed in relation to the respective upper brake block for movement therewith relative to the respective carriage assembly between the engaged position and the disengaged position.

The braking system preferably further comprises a rail sweep mounted on carriage assembly for engaging the respective rails in the railway position of the carriage assemblies. Preferably a pair of the rail sweeps mounted at longitudinally opposed ends of the frame member of each carriage assembly.

The braking system is particularly suited for vehicles supported on high rail equipment, such as a roadway vehicle having high rail equipment mounted thereon. Alternatively, the braking system may be adapted for use on rail equipment such as trains.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:

FIG. 1 is a side elevational view of the braking system mounted on a truck which has been equipped for rolling movement on a railway;

FIG. 2 is a partly sectional view along the line 2-2 of FIG. 1;

FIG. 3 is a side elevational view of the braking system in a railway position wherein the braking elements are positioned adjacent the respective rails of the railway when the vehicle is supported on the rails;

FIG. 4 is a side elevational view of the braking system in a roadway position wherein the braking elements are raised upwardly in relation to the railway position for use of the vehicle on a roadway;

FIG. 5 is an enlarged side elevational view of one carriage assembly and braking element supported thereon;

FIG. 6 is a top plan view of the carriage assembly and braking element of FIG. 5;

FIG. 7 is a sectional view along the line 7-7 of FIG. 5; and

FIG. 8 is a sectional view along the line 8-8 of FIG. 5.

DETAILED DESCRIPTION

Referring to the accompanying drawings, there is illustrated a braking system generally indicated by reference numeral 10. The braking system 10 is arranged for use with vehicles 12 which are supported on high rail equipment 14 for longitudinal rolling movement along a railway 16 comprising a pair of parallel and spaced apart rails 18.

The braking system 10 includes a mounting frame 20 which mounts a pair of braking elements 22 on the vehicle 12 so as to be laterally spaced apart transversely to the longitudinal direction of the vehicle 12. Each side generally indicated by reference numeral 24 of the mounting frame 20 mounts one of the braking elements 22 on a corresponding side of the vehicle 12.

Each side 24 of the mounting frame includes a front support arm 26 and a rear support arm 28. Both the front and rear support arms are pivotally mounted at respective top ends 30 on the frame 32 of the vehicle. The top ends 30 of the front and rear support arms are longitudinally spaced apart one in front of the other on the frame of the vehicle to extend downwardly and inwardly towards each other to respective bottom ends 34 which are coupled together.

The front support arm 26 is a telescoping member which permits adjustability of the length thereof such that the bottom ends 34 of the front and rear support arms can be pivoted upwards from a railway position as shown in FIG. 5 for use on a railway, to a roadway position as shown in FIG. 6 for use on a roadway. The rear support arm 28 comprises first and second sections wherein the second section is threadably received within the first section to permit adjustment of the length thereof in controlled amounts for controlling the position of the bottom ends 34 of the arms in the railway and roadway positions.

The front and rear support arms 26 and 28 are constrained to pivot within a fixed longitudinally extending plane which is inclined from vertical to extend downwardly and laterally outwardly from a position spaced laterally between respective sides of the vehicle. A cross support arm 36 is coupled between the respective front support arms 26 of opposing sides of the vehicle for additional support. The mounting frame provides a fixed frame in the railway position for supporting the braking elements adjacent the rails at a fixed spacing therefrom.

The braking elements 22 are mounted on respective carriage assemblies 38 which are mounted on the respective bottom ends 34 of the support arms of each respective side 24 of the mounting frame. The carriage assemblies 38 and the braking elements 22 supported thereon are mounted on the respective support arms for movement therewith between the respective railway and roadway positions.

Each carriage assembly 38 comprises an elongate frame member 100 oriented in the longitudinal direction of the vehicle. A pair of guide wheels 102 are mounted rotatably at longitudinally spaced positions on each frame member 100 adjacent opposing front and rear ends of the frame member. Each guide wheel includes a first portion 104 which is generally cylindrical in shape for rolling engagement along the top running side 76 of the head of the rail and a second portion 106 comprising an inner flange which protrudes radially outwardly from the first portion at an inner end thereof so as to be suitable for engagement with the inner side 80 of the head of the rail.

Each carriage assembly 38 is movable with the bottom ends of the support arms between the railway position in which the guide wheels are engaged in rolling movement along the respective rails and the roadway position in which the carriage assembly is spaced upwardly in relation to the railway position so as to be spaced upwardly from the rails or a roadway so as not to interfere with normal function of the vehicle on a roadway. The frame member 100 is arranged to be positioned in proximity to the inner side of the head of the respective rail in the railway position.

Each braking element 22 is mounted on the respective carriage assembly so as to be longitudinally in series between the respective pair of guide wheels 102. A pair of mounting plates 108 extend laterally outward from the frame member at longitudinally spaced positions between the two guide wheels 102 for mounting longitudinally opposed ends of the braking elements on the two mounting plates 108 respectively.

The braking elements 22 each include a housing 40 having an upper portion 42 fixed relative to the frame member 100 of the respective carriage assembly 38 and a lower portion 44 which is mounted on the upper portion 42 for sliding movement therebetween along respective axes 57 extending downward and laterally outward in relation to the vehicle.

The upper portion 42 comprises a top plate 46 and a pair of upright end plates 82 extending downward from longitudinally opposed ends of the top plate. Each end plate 82 is bolted in fixed relation to a respective one of the mounting plates 108 so that the upper portion 42 of each braking component is fixed relative to its respective carriage assembly 38.

The top plate 46 also includes a mounting portion on the bottom side thereof at a central location which supports a pair of downwardly facing cylinders 48 below the top plate. The mounting portion on the bottom side of the top plate also supports a pair of channels 50 extending downwardly therefrom as described in further detail below.

The lower portion 44 includes a lower plate 52 which is substantially parallel and spaced below the top plate 46 of the upper portion. The lower plate 52 mounts a pair of pistons 54 thereon which are aligned with and received within the respective cylinders 48 of the upper portion 42. A pair of upright guide plates 56 extend upwardly from the lower plate 52 for alignment with the respective channels 50 in the upper portion of the housing so as to support the lower portion 44 for sliding movement in the channels 50 relative to the upper portion 42. An inclined sliding guide block 55 is mounted between the guide plates 56 and the channels 50 to support the guide plates for sliding movement constrained along respective axes which extend downwardly and laterally outwardly in relation to the vehicle as indicated by reference numeral 57.

A pair of helical springs 58 are mounted between the top plate 46 and the lower plate 52 at opposing ends of the housing so as to bias the lower portion 44 of the housing upwardly adjacent the upper portion 42.

A hydraulic fluid line 60 supplies the cylinders 48 with hydraulic fluid above the pistons 54 so as to urge the pistons and the lower portion 44 of the housing downwardly relative to the upper portion of the housing when pressurized hydraulic fluid is received therein. The cylinders 48 and the porting to the cylinders from the hydraulic fluid line 60 are formed in a base member 62 which is bolted in position on a pair of mounting channels 64 on a bottom side of the top plate 46.

The guide plates 56 each include a stop member 66 adjacent a top end thereof. A stop bolt is fitted through the aperture in each stop member 66 and a corresponding aperture 70 in the top plate 46 for engaging the stop member 66 and limiting the downward travel of the lower portion 44 of the housing relative to the upper portion 42 as desired. The stop bolt 68 includes a nut which is threaded on a bottom end thereof spaced below the stop member 66 such that downward travel of the lower portion 44 of the housing is limited when the stop member engages the nut on the end of the stop bolt 68. By adjusting the position of the nut on the bolt by rotation of the nut on the threads of the bolt, the permissible amount of displacement between the upper and lower portions of the housing is controlled.

A bottom side of the lower plate 52 mounts an upper brake block 72 and a side brake block 74 thereon. The upper brake block 72 comprises a plurality of longitudinally spaced brake pads having a downwardly facing braking surface arranged to engage a top running side 76 of the head of the rail. The side brake block 74 extends downwardly from an inner side 78 of the upper brake block 72 at substantially right angles thereto such that the braking surface of the side brake block 74 faces laterally outwardly for engaging an inner side 80 of the head of the rail. The side brake block 74 also comprises a plurality of longitudinally spaced brake pads wherein the brake pads are mounted on the respective brake blocks by removable fasteners such that the brake pads are selectively separable from the housing 40 to replace the pads as needed when the pads wear out. The upper and side brake blocks 72 and 74 are fixed together on the lower plate 52 to be urged downwardly and outwardly together by the pistons 54 operating in the hydraulic cylinders 48 for engagement with the rails in an engaged braking position.

In addition to the guide wheels 102, each carriage assembly 38 also supports a pair of rail sweep assemblies at respective front and rear ends of the frame member 100 so as to be positioned longitudinally outward relative to the guide wheels. A rail sweep mounting plate 110 extends laterally inwardly from each of the front and rear ends of each frame member 100. Each rail sweep assembly comprises an outer rail sweep 84 and an inner rail sweep 86 bolted onto the respective rail sweep mounting plate 110. The bottom ends of the rail sweeps are similar in elevation to the bottom sides of the guide wheels such that when the guide wheels engage the rails in the railway position, the rail sweeps extend downwardly from the frame member of the carriage assembly so that the bottom ends are close proximity to the rails for scraping debris from the top side of the rails in the railway position. The rail sweeps are arranged such that the outer rail sweep 84 is formed of rubber and extends downwardly further than the inner rail sweep 86 which is formed of a suitable metal.

A pair of hydraulic linear actuators 90 are mounted between the vehicle frame 32 and the carriage assemblies 38 respectively such that the actuators are mounted at respective sides of the vehicle 12. Linear expansion and retraction of the piston cylinder of each linear actuator 90 acts to displace the carriage assemblies on the bottom ends 34 of the support arms between the respective railway and roadway positions thus displacing the braking elements 22 towards and away from the respective rails 18.

The hydraulic actuators 90 are arranged to displace the carriage assemblies 38 and the braking elements 22 thereon along respective arcs dictated by the pivoting support arms 28. More specifically the braking elements 22 are urged downwardly and laterally outwardly away from each other from the roadway position towards the railway position as indicated by arrow 92.

A hydraulic supply 120 is provided on the vehicle for supplying hydraulic fluid to extend and retract the actuators 90 as desired. The hydraulic supply 120 has an output which provides a continuous active hydraulic pressure at a pre-set prescribed pressure level using appropriate pressure reducing and/or pressure relieving valve arrangements. Accordingly, in the railway position, the actuators 90 continue to apply pressure at the prescribed level to maintain positive engagement of the guide wheels on the rails. This in turn supports the rail sweeps at a prescribed elevation relative to the rails as well as supporting the brake blocks at a prescribed elevation relative to the rails.

The prescribed pressure level can be adjusted and pre-set to any pressure level throughout of range of selectable pressure levels. Typically the pressure level is adjusted at one time according to the vehicle size and/or to which the braking system is applied. It is desired to dynamically maintain a positive pressure to maintain engagement of the guide wheels with the rails, but to limit the pressure so that the braking system does not undesirably lift or reduce driving traction of primary wheels of the vehicle relative to the rails.

The hydraulic pistons 54 act as actuators for displacing the brake blocks downwardly and outwardly along respective axes in relation to the respective housings and carriage assemblies upon which they are supported between a disengaged position as shown in FIG. 4 and the engaged braking position in which the brake blocks engage the respective rails in a braking action. In the disengaged position, the brake blocks are disengaged from the rails and maintained at a prescribed space from the respective surfaces of the rails as controlled by the engagement of the guide wheels with the rails. When the hydraulic pistons 54 are actuated, the brake blocks are displaced relative to the carriage assemblies so that braking force is applied to the vehicle 12 by frictionally engaging the upper brake blocks with the respective top sides of the heads of the rails in addition to providing a wedging action of the side brake blocks engaging between the respective inner sides of the heads of the rails. The wedging action provides considerable braking force to the vehicle by pushing against opposing rails as opposed to clamping on a single rail.

When the vehicle is used on normal roadways, the braking elements 22 are retracted using the support arms 26 and 28 into the roadway position of FIG. 6. When the high rail equipment 14 is engaged for supporting the vehicle 12 on a railway 16, the braking elements 22 are subsequently displaced into the railway position adjacent to the respective rails at a fixed spacing therefrom by engaging the rails with the guide wheels. When braking force is desired to slow the vehicle down when rolling on the railway 16, the hydraulic actuators in the form of pistons 54 are activated to urge the brake blocks into firm engagement with the respective heads of the rails and to wedge the brake blocks between the respective inner sides of opposing rails.

In further variations of the present invention other fixed frames may be provided for mounting the braking elements 22 onto a vehicle 12 while permitting relative movement of the braking elements downwardly at a laterally outward incline to wedge between opposing inner sides of the respective rails. The braking elements 22 are thus adaptable to various types of rail equipment including maintenance trucks and construction vehicles having high rail equipment mounted thereon. Furthermore, the support arms may be replaced with a linkage arrangement for pivoting the braking elements downward and laterally outward along an arcuate path as opposed sliding movement along a fixed axis.

While one embodiment of the present invention has been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention. The invention is to be considered limited solely by the scope of the appended claims. 

1. A braking system for rail equipment which is arranged to be supported on a pair of rails for movement in a longitudinal direction along the rails, the braking system comprising: a pair of carriage assemblies, each carriage assembly comprising a frame member and a pair of guide wheels rotatably mounted on the frame member at longitudinally spaced positions; rail equipment mounting means arranged to support the carriage assemblies on the rail equipment such that the carriage assemblies are movable between a railway position in which the guide wheels of the pair of carriage assemblies are arranged for rolling engagement along respective ones of the rails and a roadway position in which the carriage assemblies are spaced upwardly from the railway position; a braking component comprising at least one brake block supported on each carriage assembly such that said at least one brake block is movable relative to the respective carriage assembly between an engaged position in which said at least one brake block engages the respective rail in a braking action and a disengaged position in which said at least one brake block is disengaged from the respective rail while the carriage assembly remains in the railway position; and an actuator arranged to selectively urge the brake blocks of the carriage assemblies towards the engaged position.
 2. The braking system according to claim 1 wherein the rail equipment mounting means comprises hydraulic actuators for urging the carriage assemblies from the roadway position to the railway position and wherein the braking system further comprises a hydraulic supply in connection with the hydraulic actuators of the rail equipment mounting means which is arranged to supply an active hydraulic pressure at a prescribed pressure level to the hydraulic actuators of the rail equipment mounting means.
 3. The braking system according to claim 2 wherein the prescribed pressure level comprises a set-point pressure which can be controllably adjusted through a range of selectable pressures.
 4. The braking system according to claim 1 wherein each guide wheel includes a generally cylindrical portion arranged for rolling engagement along a top side of a head of the respective rail and an inner flange portion which protrudes radially outwardly from the generally cylindrical portion at an inner end thereof in proximity to an inner side of the head of the respective rail.
 5. The braking system according to claim 1 wherein the rail equipment mounting means is arranged to support the carriage assemblies on the rail equipment such that the carriage assemblies are movable downwardly and laterally outwardly from the roadway position to the railway position.
 6. The braking system according to claim 1 wherein said at least one brake block of each carriage assembly comprises an upper brake block arranged to engage a top side of a head of the respective rail and a side brake block arranged to engage an inner side of the head of the respective rail.
 7. The braking system according to claim 6 wherein the brake blocks are slidably mounted on the respective carriage assemblies for sliding movement along respective axes extending downward and laterally outward from the disengaged position towards the engaged position.
 8. The braking system according to claim 6 wherein each side brake block is fixed in relation to the respective upper brake block for movement therewith relative to the respective carriage assembly between the engaged position and the disengaged position.
 9. The braking system according to claim 1 wherein there is provided a rail sweep mounted on carriage assembly for engaging the respective rails in the railway position of the carriage assemblies.
 10. The braking system according to claim 9 wherein there is provided a pair of rail sweeps mounted at longitudinally opposed ends of the frame member of each carriage assembly. 